1. Field of the Invention
This invention relates to an apparatus for automatically placing valve vented bags on a filling spout of a packaging machine. More particularly, the invention relates to an apparatus for automatically opening valve vented bags, for transferring the opened bags from a bag conveyor, and for placing the opened bags alternately on plural filling spouts of a packaging machine or the like.
2. Information Disclosure Statement
Traditionally, the filling and closing of bags containing powdery or granular material has been accomplished by pouring the material into the bag and sewing the top edge of the bag to provide a spill-proof seal to the package. With the advent of valve vented bags, the speed with which bags can be filled and sealed has been greatly increased. The valve vented bag is a bag usually fabricated from a sheet of relatively thick paper and having the top seam folded in such a way that a flap valve is integrally provided in the top of the bag. When the opened flap valve is placed over a filling spout of a packaging machine or silo, the material to be packaged is fed directly into the bag. When the bag has been filled, the bag is slipped off the filling spout and the flap valve automatically seals the bag against spillage by virtue of the internal pressure exerted on the flap valve by the contents of the bag.
In the cement packaging art, the majority of packaging machines include a row of four filling spouts. Filling of bags has been carried out manually by having an operator remove bags, one at a time, from a stack of bags and placing the bags, one at a time, onn the filling spouts. Although the filled bags sometimes disengage from the filling spout when full, as often as not it becomes necessary to manually pull the filled bag off the spilling spout. Obviously, the aforementioned manual packaging process is time consuming and costly. Additionally, in view of the environment encountered in the vicinity of the filling spouts, face masks and eye protective equipment must be worn by the operator. In addition, the speed with which bags can be filled is very limited and an experienced bag placer will find difficulty in maintaining a speed of twenty or more bags per minute for any extended period.
In view of the aforementioned problems related to the bag placing art, several proposals have been made in an attempt to fully automate the packaging of powdery or granular materials. One such proposal is that known in the art as the ROTO-PACKER (registered trademark) produced by Haver & Boecker. The ROTO-PACKER replaces the conventional packaging machine by a rotary type packaging machine having radially extending filling spouts. A reel or roll of 2,000 to 3,000 bags feeds a shingled row of bags to the bag placing mechanism which transfers the bags, one at a time, to one of the filling spouts as the filling spouts rotate into a bag placing station. Such automatic bag placers have greatly increased the overall speed with which bags can be placed and filled. Operating speeds of 33-36 bags per minute are possible. However, although the automatic bag placer of U.S. Pat. No. 3,138,217 assigned by Haver & Boecker provides a high speed packaging machine, the cost of removing an existing packaging machine and replacing the same with a ROTO-PACKER could probably reach $500,000 per installation. Such high installation costs can rarely be justified relative an existing packaging plant, and a need has existed in the art of an automatic bag placer which will operate to place opened bags on the row of filling spouts of a conventional packaging machine.
U.S. Pat. No. 3,715,858 to Durant et al discloses an automatic bag placer for placing the opened bags on the filling spouts of a conventional packaging machine. However, the bags are fed from a stack of bags. Such a stack of bags would only run for approximately one-half hour and would therefore require an operator to be employed full time to provide a constant supply of bags.
The automatic bag placer of the present invention overcomes the aforementioned inadequacies of the prior art devices by providing an automatic bag placer for use with a conventional packaging machine, the bag placer being fed with bags supplied from a roll of such bags. A bag placer according to the present invention has successfully operated at a speed of 20 bags per minute when installed for use with a conventional packaging machine having four filling spouts in a row. It is the primary object of the present invention to provide a relatively low cost apparatus which can be installed for operation with a conventional packaging machine having filling spouts in a row.
Another object of the present invention is the provision of an automatic bag placer in which the bags are fed to the bag placing mechanism from a roll or reel of valve vented bags.
Another object of the present invention is the provision of a first suction cup which is retractable relative the path of the bags being fed towards the bag placing mechanism.
Another object of the present invention is the provision of a first bag gripper having a pair of jaws which grip the open bag when the bag is held in the open position by the suction cup device.
Another object of the present invention is the provision of a first bag gripper which moves from a tilted disposition when gripping the open bag held by the suction cup device to a dependent disposition when transferring the open bag towards the filling spout.
Another object of the present invention is the provision of a first bag gripper which rotates through a one-quarter revolution when in a dependent disposition such that the open bag is aligned for the entry therein of the filing spout.
Another object of the present invention is the provision of a first carriage for rotatably supporting the first bag gripper.
Another object of the present invention is the provision of a first pair of rails for supporting and guiding the carriage between the first table and the filling spout.
Another object of the present invention is the provision of a pair of rails pivotably mounted relative to the bag placer frame such that the first carriage is alternately guided towards a first filling spout and then a second filling spout.
Another object of the present invention is the provision of a first and a second bag conveyor, a first and a second roll of valve vented bags, a first and a second table, a first and a second bag clamp, a first and a second suction cup device, a first and a second bag gripper, a first and a second carriage, a first pair of rails for guiding the first carriage alternately towards a first and a second filling spout of a packaging machine, and a second pair of rails for guiding the second carriage alternately towards a third and a fourth filling spout of the packaging machine.
Another objective of the present invention is the provision of an automatic bag placer in which the bag clamps, the suction cups, the bag gripper, the bag carriage and the rails are moved by pneumatic means.
Another objective of the present invention is the provision of a computerized control circuit for regulating the operation of the pneumatic rams.
The foregoing has outlined some of the more pertinent objects of the present invention. These objects should be construed to be merely illustrative of some of the more prominent features and applications of the invention. Many other beneficial results can be attained by applying the disclosed invention in a different manner or modifying the invention within the scope of the invention. Accordingly, other objects and a fuller understanding of the invention may be had by referring to the summary of the invention and the detailed description describing the preferred embodiment in addition to the scope of the invention defined by the claims taken in conjunction with the accompanying drawings. This should not be construed as limited to bag placers for use with cement packaging machines but should include bag placers for packaging machines for packaging any powder or granular material or the like into bags and should not be limited to packaging machines having four filling spouts.